I've mentioned before, but the best 0-30 ohm sender unit I've found is one that was created in Taiwan and is sold on eBay by a seller whose id is renbusan. It is accurate and clever. The wiper never touches the resistance material but runs across precision metal fingers instead. And it wipes in a flat plane and not in an inverted arc, so it remains accurate. Body is all nylon. About $30 delivered last I looked.
